Month: March 2016

Easter and couple of days of free time is good for taking a break from the routines or finally have some time to develop your personal pet projects. At least my Highkara news reader for iOS needs some UI tests for screenshots and maybe I get to finish my imgur app for tvOS. But before that here’s the weekly notes.

This week we get overview to OWASP projects, see how Stack Overflow is built, learn to design for the Apple TV and get to run WebLogic on Docker container. Finally we discover how Spotify Discover Weekly playlists work.

Why I Left Gulp and Grunt for npm Scripts
Cory House explains how Gulp and Grunt are unnecessary abstractions, whereas npm scripts are plenty powerful and often easier to live with. It’s easier to debug as there’s no extra layer of abstraction, there’s no dependence on plugin authors to update, original tool is better and clearer documented. (from Web Design Weekly #219)

iOS and tvOS development

An in-app debugging and exploration tool for iOS
Excellent tool for iOS developer which helps you for example to simulate 3D Touch in the Simulator. Also in Xcode 7.3 you can now simulate 3D Touch without external tools if your trackpad has Force Touch.

Designing for the Apple TV
Michael Flarup writes some tips for getting design right when working with the Apple TV. He covers all of the basics but also some interesting points like making sure you meet the expectations of a TV based platform in terms of displaying and taking advantage of video based content. (from iOS dev Weekly #239)

Enterprise Java

WebLogic on Docker Containers Series: Part 1, Part 2 and Part 3
If you are using WebLogic as your application server, you should have a look at Bruno Borges series about running WebLogic on Docker. First post gets you started and shows how to create a basic Docker image with WebLogic and one with a configured WebLogic domain. The second post takes a more detailed look at the creation of the images, and the third one focusses on the domain configuration. (from Java Weekly 8/16)

Development and Operations, DevOps, is one of the important things when going beyond agile. It’s boosting the agile way of working and can be seen as an incremental way to improve our development practices. And what couldn’t be a good place to improve than learning at meetups how others are doing things. This time DevOps Finland meetup was about container orchestration with CoreOS and it was held at Oppex’s lounge in central Helsinki. The talks gave a nice dive into CoreOS, covering both beginner and seasoned expert points of view. Here’s my short notes about the presentations.

CoreOS intro for beginners, by beginners

The first talk was practically an interactive Core OS tutorial by Antti Vähäkotamäki and Frans Ojala. Their 99 slides showed how to get started with CoreOS on Vagrant step by step and what difficulties they experienced. Nothing special.

CoreOS in production, lessons learned

The more interesting talk about CoreOS was “CoreOS in production, lessons learned” by Vlad Bondarenko from Oppex where he told about their software stack and how they’re running it. In short, they’re running on baremetal with CoreOS Nginx for reverse proxy, Node.js for UI and API and RethinkDB and SolrCloud clusters. Deployment is made with Ansible and makefiles and Ship.it is used for Node.js. Service discovery is DNS based with docker-etcd-registrator component and they’ve also written their own DNS server. For Node.js config management with etcd they’ve made etcd-simple-config component. With Docker they use standard images with volumes and inject own data to the container.

CoreOS seemed to work quite well for them with easy cluster management, running multiple versions of 3rd party and own software and having zero downtime updates or rollbacks. But there were some cons also like maturity (bugs) and scripting systemd.

Kontena, CoreOS war stories

The last talk was about CoreOS war stories in Kontena by Jari Kolehmainen. The slides tell the story of how they use CoreOS on Kontena and what are the pain points. In story short it comes to configuration management and issues related to etcd.

For bootstrapping they use CloudInit which is de-facto way to initialize cloud instances and Integrated to CoreOS. The hard parts with etcd are discovery, security (tls certificates), using central services vs. workers and maintenance (you don’t do it). Now they run etcd inside a container, bind it only to localhost and overlay network (Weave Net) and master coordinates etcd discovery. With automatic updates they use the best-effort strategy: If etcd is running, locksmith coordinates the reboots; Otherwise just reboot when update is available.

Presentation’s summary was that the “OS” part is currently best option for containers and etcd is a must, but a little hard to handle. For the orchestrator they suggest that pick one which hides all the complexities. And automate all the things.